he Distributed Multi-GNSS Timing and Localization (DiGiTaL) 2.0 system will leverage an existing partnership between Tyvak and the Stanford’s Space Rendezvous Laboratory (SLAB) to advance the development required to provide precise knowledge of absolute and relative states of multiple orbiting nanosatellites necessary to mimic a gigantic spacecraft though a swarm of spacecraft with adjustable baselines. Cooperative swarms of space vehicles have the potential to change fundamentally how many future space missions are performed. By distributing payload tasks among multiple coordinated units, referred to as a Distributed Space Systems (DSS), rather than on a monolithic single spacecraft, advanced missions in Earth and planetary science, on-orbit servicing, and space situational awareness are possible. Centimeter-level relative positioning precision can be obtained from Global Navigation Satellite Systems (GNSS) using differential carrier-phase techniques, where synchronous measurements are shared between spacecraft and error-cancelling combinations of various data types are formed to create precise baseline knowledge. Combined with the innovation Tyvak is leading in spacecraft miniaturization, whereby micro- and nanosatellites are transitioning from being merely educational tools to a viable scientific platform, future missions not possible on a monolithic spacecraft are enabled. We will use the challenging miniaturized Distributed Occulator/ Telescope (mDOT) astrophysics mission as a reference to provide actual requirements to inform the development.
The improvement of positioning, timing, and navigation of spacecraft swarms is a stepping stone to enable sparse cooperative apertures with breakthrough applications which span the NASA scientific portfolio including Earth and Space Science. The proposed DiGiTaL 2.0 system will support different communication architectures required by the Exploration portfolio and will impact substantially NASA future missions.
Like the NASA applicability above, there are many non-NASA applications for this technology. Sparse apertures can be used for communication, imaging throughout the electromagnetic spectrum, and many other missions that are performed by non-NASA government and commercial entities.